Positioning means for pistons



Patented July 24, 1923.

FFEQ

LEWIS DAVIS AND ROBERT M. HUGHES, OF SAN FRANCISCO, CALIFORNIA.

POSITIONING MEANS FOR PISTONS.

Application filed October 10,1921. SeriaI No. 506,795.

To all whom it 'mae concern:

Be it known that we, LEWIS R. DAVIS and ROBERT M. Hncnris, citizensofthe United States, and residents. respectively, of San Francisco,countyof San Francisco and State of California, have invented a new anduseful Positioning Means for Pistons, of which the following is aspecification.

The present invention relates to improvements in positioning means forpistons or the like and itsparticular object is to provide means forpositioning the internal studs of a piston so as to aline the same witha drill guide for the purpose of boring a hole through the studs adaptedto receive the wrist pin to which the connecting rod is attached. Ourdevice is particularly adapted to facilitate the positioning of the studand to accomplish the latter object with very little loss of-time andwith machine-like accuracy. I f V The preferred form of our device isshown in the accompanying drawing in which Figure 1 represents a topplan view of our device'and Figure 2 a side elevation of the sameshowing the piston in its place, but part of the same broken away so asto disclose the interior.

It will be understood that slight changes or modifications might be madewithout departing from the spirit of the invention or leaving the scopeof the claims hereto attached.

The frame member (1), comprising a horizontal plate (2), a verticaltransverse flange and two longitudinal flanges (4) and (5), is securedto the base plate by means of the bolts A second frame member (9),comprising a horizontal. plate (11) and a vertical transverse flange(12), is adjustably secured to the same base (7) in parallel relation tothe frame member (1) by means of two bolts (14), the heads of whichslidably engage grooves (15) in the base plate in the manner shown inthe drawing, while the nuts (16), when screwed tightly on the bolts,force the horizontal plate (11) into firm contact with the base plate soas to secure the former plate against sliding motion. In this manner thedistance between the two vertical flanges and (12) may be changed atwill. The flange (3) is provided with a cone-shaped projection (21)which is axially alined with an opposing centering device (22) supportedin the flange (12) in co-operative relation with the conical projection(21). The centering device consists of a pointed pin (23) slidablysupported in a boss (24) secured on the frame member (12) and adapted tobe moved back and forth by means of the hand wheel (26) actuating ascrew (30), in a well known manner. It will be understood that thedevice thus far described serves for the support of the piston (27) 011the axis defined by the cone (21') and the centering device (22). It isadjustable by means of the bolts (14) sliding in the grooves (15) toreceive within reasonable limits any size of piston desired which'may bequickly placed in position by being slipped over the cone with its openendand by then being engaged by the centering device (22) in its center,whereupon a moving forward of the centering device by means of the handwheel (26) will force the piston into the desired position.

Over the two flanges and (12), which are of equal height, the plate (29)is supported and held in position by means of bolts (31). It will benoticed that the plate it provided with a longitudinal slot (32) ateither end so that the position of the plate relative to the framemembers is adjustable. The plate is provided preferably in its centerwith a perforation (30) which latter extends also through the boss (33)forming an integral part of the plate (29). This perforation (30) servesas a guide for the drill and it is the principal object of the presentinvention to provide means which will mechanically aline the studs (34)iI1- side the piston with the perforation (30) so that a drill guidedthrough the latter perforation will strike the studs centrally. Toaccomplish this we provide a preferably square bar (36) which issupported in the frame member (1) in axial alinement with the cone (21)and the centering device (22), and which may be pushed forward andbackward by means of the handle (37), which rests slidably on the flange(5) and is pivotally supported in a somewhat higher portion of theflange (4) by means of the pin (38). The handle extends through ahorizontal slot (39) in the bar (36), the slot being shaped as shown inFigure 1 so as to allow the handle to work the bar in the mannerdesignated. The bar extends into the piston as shown in the drawing andslidably supports at its end a vertical member (41), the other end ofwhich ex Lil tends into operative proximity with one of the studs (34)and is provided with a fork (42) shaped as shown in dotted lines inFigure 1 and presenting two inner faces (43) slanting toward each otherand adapted to engage the stud (34). The member (41), the exact positionof which may be regulated by means of the set screw (44) is alwaysparallel to the axis of the drill guide and the fork is arrangedsymmetrically on the member (41 so that whenever the fork is in firmengagement with the stud (34) the latter must be axially alincd with thedrill guide (32).

It will thus be seen that after the piston has been properly centered inthe manner hereinbefore described and one of the studs (34) has beenpositioned approximately in line with the drill guide, it is onlynecessary to push the bar (36) forward by means of the handle (37) whenthe fork will engage the stud (34) and force the same into exactalinement with the drill guide.

l/Ve claim:

1. A drill jig for holding pistons having an internal stud, comprisingmeans for axially supportin' the tube and means engaging the stu foradjusting its position relative to the axis of the tube, said meanscomprising a fork having two inclined inner surfaces adapted to engagethe stud and sliding means for intensifying the engagement whereby thestud is forced into a central position relative to the fork.

2. A drilljig for holding pistons having an internal stud relative to adrill guide, comprising means for axially supporting the tube so as tobring the stud into the transverse plane of the drill guide and meansfor axially alining the stud with the latter, said means comprising afork having two inclined inner surfaces adapted to engage the stud andsliding means for intensifying the engagement whereby the stud is forcedinto a central position relative to the fork.

3. A machine for drilling a diametrical hole through an internal stud ofa piston,

com risin a drill uide means for osii b V D.. i7

tioning the piston transversely of the drill axial centering means forthe piston sup-.

ported in the frame members, a drill guide adjustably supported on theframe members adapted to be brought into the transverse plane of thestud, and means supported in one frame member for axially alining thestud with the drill guide, said means comprising an angular barslidingly supported in the frame member in axial alinement with thepiston, and means associated therewith for positioning the stud.

5. A machine for drilling a diametrical hole through an internal stud ofa piston, comprising two frame members adjustably supported in spacedrelation to each other, i

axial centering means for the piston supported in the frame members, adrill guide adjustably supported on the frame members adapted to bebrought into the transverse plane of the stud, and means supported inone frame member for axially alining the stud with the drill guide, saidmeans comprising an angular bar slidingly supported in the frame memberin axial alinement with the piston, a fork associated therewith havingtwo inclined inner surfaces for engaging the stud and manually actuatedmeans for intensifying the engagement between the fork and the studwhereby the latter is centered relative to the former.

LElVIS R. DAVIS.

ROBERT M. HUGHES.

